APA
Gilkey L., . (1979). Message and existence. New York: Seabury Press.
Chicago
Gilkey Langdon, . 1979. Message and existence. New York: Seabury Press.
Harvard
Gilkey L., . (1979). Message and existence. New York: Seabury Press.
MLA
Gilkey Langdon, . Message and existence. New York: Seabury Press. 1979.